1. Field of the Invention
This invention relates to method of manufacturing components which are adapted to be mounted on shafts particularly for steering shafts of a vehicle.
2. Description of the Prior Art
Conventional die cast components, such as steering wheel hubs, which are adapted to be mounted on a shaft, include a central aperture by means of which the component is attached to the shaft. The internal surface of the aperture is cylindrical and is usually splined so that the component can be non-rotatably fixed to the shaft. Where the end of the shaft is to be fixed in the mounting, part of the internal surface usually diverges outwardly towards the end of the aperture. This divering surface engages with a complementary surface on the shaft so that the relative axial positions of the component and shaft are fixed.
For reasons of cost, it is desirable to use material other than steel, e.g. aluminum, in the manufacture of components such as steering wheel hubs. However, in some cases, aluminum does not have sufficient strength to permit a direct splined connection between the component and the shaft. Consequently, such components manufactured from aluminum sometimes include a central tubular insert of stronger material, e.g. steel, into which splines can be machined. In the manufacture of such components, the insert is loaded into a die, and the material from which the body of the hub is to be made, e.g. aluminum is then introduced into the die around the insert. In practice, it frequently occurs that the insert is loaded into the die in an incorrect orientation so that the insert is positioned upside-down in the finished component. Where the component is intended to be fixed onto the shaft in one orientation only, the resulting component is useless.